Update granite and water

src/porepy/params/rock.py

@@ -3,6 +3,8 @@
 Contains standard values (e.g. found in Wikipedia) for permeability, elastic
 moduli etc.
 
+Note that thermal expansion coefficients are linear (m/mK) for rocks, but
+volumetric (m^3/m^3) for fluids.
 """
 import porepy as pp
 
@@ -157,7 +159,7 @@ def __init__(self, theta_ref=None):
         self.PERMEABILITY = 1e-8 * pp.DARCY
         self.POROSITY = 0.01
         # Reported range for Young's modulus by jsg is 10-70GPa
-        self.YOUNG_MODULUS = 4.0 * pp.GIGA * pp.PASCAL
+        self.YOUNG_MODULUS = 40.0 * pp.GIGA * pp.PASCAL
         # Reported range for Poisson's ratio is 0.125-0.25
         self.POISSON_RATIO = 0.2
 
@@ -166,9 +168,8 @@ def __init__(self, theta_ref=None):
         self.LAMBDA, self.MU = lame_from_young_poisson(
             self.YOUNG_MODULUS, self.POISSON_RATIO
         )
-        self.THERMAL_EXPANSION = (
-            8e-6 * pp.METER / (pp.METER * pp.CELSIUS)
-        )  # from engineeringtoolbox.com
+        # Units of thermal expansion: m^3 / m^3 K, i.e. volumetric. From engineeringtoolbox.com
+        self.THERMAL_EXPANSION = 8e-6 * pp.METER / (pp.METER * pp.CELSIUS)
         if theta_ref is None:
             self.theta_ref = 20.0 * pp.CELSIUS
         else:

src/porepy/params/water.py

@@ -1,3 +1,10 @@
+""" Hard coded typical parameters that may be of use in simulations.
+
+Contains standard values (e.g. found in Wikipedia) for density, thermal properties etc.
+
+Note that thermal expansion coefficients are linear (m/mK) for rocks, but
+volumetric (m^3/m^3) for fluids.
+"""
 import numpy as np
 import porepy as pp
 
@@ -13,20 +20,23 @@ def __init__(self, theta_ref=None):
         self.BULK = 1 / self.COMPRESSIBILITY
 
     def thermal_expansion(self, delta_theta):
+        """ Units: m^3 / m^3 K, i.e. volumetric """
         return (
             0.0002115
             + 1.32 * 1e-6 * delta_theta
             + 1.09 * 1e-8 * np.power(delta_theta, 2)
         )
 
     def density(self, theta=None):  # theta in CELSIUS
+        """ Units: kg / m^3 """
         if theta is None:
             theta = self.theta_ref
         theta_0 = 10 * (pp.CELSIUS)
         rho_0 = 999.8349 * (pp.KILOGRAM / pp.METER ** 3)
         return rho_0 / (1.0 + self.thermal_expansion(theta - theta_0))
 
     def thermal_conductivity(self, theta=None):  # theta in CELSIUS
+        """ Units: W / m K """
         if theta is None:
             theta = self.theta_ref
         return (
@@ -37,11 +47,13 @@ def thermal_conductivity(self, theta=None):  # theta in CELSIUS
         )
 
     def specific_heat_capacity(self, theta=None):  # theta in CELSIUS
+        """ Units: J / kg K """
         if theta is None:
             theta = self.theta_ref
-        return (4245 - 1.841 * theta) / self.density(theta)
+        return 4245 - 1.841 * theta
 
     def dynamic_viscosity(self, theta=None):  # theta in CELSIUS
+        """Units: Pa s"""
         if theta is None:
             theta = self.theta_ref
         theta = pp.CELSIUS_to_KELVIN(theta)